Goodwill and Other Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2015

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Other Intangible Assets

 Intangible assets and associated amortization expense were as follows:

millions	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Amortization Expense
December 31, 2015
Offshore platform leases	$	33	$	(31	)	$	2	$	2
Customer contracts	980		(46		)	934		31
	$	1,013	$	(77	)	$	936	$	33
December 31, 2014
Offshore platform leases	$	33	$	(29	)	$	4	$	—
Customer contracts	1,004		(15		)	989		6
	$	1,037	$	(44	)	$	993	$	6